The interface between inhibition of descending noradrenergic pain control pathways and negative affects in post-traumatic pain patients

Figures & data

Table I. Demographic characteristics of study subjects (mean ± SEM).

Group	n	Age (y)	Height (cm)	Weight (kg)	Sex (M/F)	Pain intensity (VAS)^a	Pain duration (h)
Trauma	30	31.5 ± 1.2	165.5 ± 1.4	63.2 ± 1.9	18/12	6.75 (3.6,7.6)	9.8 ± 1.3
Pain-free group	33	32.9 ± 1.1	165.6 ± 1.4	64.1 ± 1.7	19/14	0	0
Painful active labor	30	29.8 ± 0.6	159.1 ± 0.4^b	68.8 ± 0.8^c	0/15	6.2 (4.8,7.6)	9.6 ± 1.1
Elective cesarean section	31	30.3 ± 0.8	159.5 ± 0.7^b	69.2 ± 0.8^c	0/15	0	0

^aMedian (percentiles 25, 75).

^b P < 0.05 versus trauma group and pain-free group, but not different from female patients.

^c P < 0.05 versus trauma group and pain-free group, using a separate analysis compared to the female patients.

Figure 1. Release of monoaminergic transmitters and their end-products in CSF. Group 1 is post-traumatic pain group, group 2 is pain-free group, group 3 is painful active labor group, and group 4 is elective cesarean section group. NA= noradrenaline; MHPG = 3-methoxy-4-hydroxyphenylglycol; DOP = dopamine; 5-HIAA = 5-hydroxyindoleacetic acid; HVA = homovanillic acid. ^‡ P < 0.01 versus group 2, 3, 4; *P < 0.05 versus group 2; ^† P < 0.01 versus group 4.

Table II. Pain assessment results.

Group	SF-MPQ(t)	SF-MPQ(s)	SF-MPQ(a)	VAS
Trauma	19.0 (8.75,24)	14.5 (6,18)	4.5 (2,7)^a	6.75 (3.6,7.6)
Painful active labor	18 (12,22)	14 (9,17)	3 (2,4)	6.2 (4.8,7.6)

All VAS pain scores values and SF-MPQ pain scores values were represented in median (percentiles 25, 75).

^a P < 0.05 versus active, painful labor group.

SF-MPQ = short form of the McGill pain questionnaire; t = aggregate value of the SF-MPQ; s = sensory items of SF-MPQ; a = affective items of SF-MPQ; VAS = visual analogue score.

Table III. Correlation analysis of monoaminergic transmitters and metabolites with pain assessment.

	NA	MHPG	DOP	5-HIAA	HVA
Trauma
VAS	–0.367^a	–0.100	0.231	0.316	–0.068
SF-MPQ(t)	–0.388^a	–0.103	0.225	0.307	–0.132
SF-MPQ(s)	–0.357	–0.068	0.225	0.319	–0.146
SF-MPQ(a)	–0.433^a	–0.147	0.202	0.299	–0.112
Painful active labor
VAS	0.102	0.119	–0.021	0.418^b	0.005
SF-MPQ(t)	0.181	0.096	–0.057	0.463^b	0.087
SF-MPQ(s)	0.173	0.086	–0.062	0.439^b	0.100
SF-MPQ(a)	0.226	0.016	–0.132	0.479^b	0.141

Correlations coefficients on a comparison between monoaminergic transmitters (and metabolites) and pain assessed as score values.

^a P < 0.05.

^b P < 0.01.

SF-MPQ = short form of the McGill pain questionnaire; t = aggregate value; s = sensory items; a = affective items; VAS = visual analogue score; NE = norepinephrine; MHPG 3-methoxy-4-hydroxyphenylglycol; DOP = dopamine; 5-HIAA = 5-hydroxyindoleacetic acid; HVA = homovanillic acid.